code: def forward(self, x):
      f = []
      x = self.conv1(x)
  
      x = self.bn1(x)
      x = self.relu1(x)
  
      x = self.conv2(x)
      x = self.bn2(x)
      x = self.relu2(x)
  
      x = self.maxpool1(x)
      x = self.layer1(x)
  
      x = self.conv3(x)
      x = self.bn3(x)
      x = self.relu3(x)
      f.append(x)
  
      x = self.maxpool2(x)
      x = self.layer2(x)
  
      x = self.conv4(x)
      x = self.bn4(x)
      x = self.relu4(x)
      f.append(x)
  
      x = self.maxpool3(x)
  
      x = self.layer3(x)
      x = self.conv5(x)
      x = self.bn5(x)
      x = self.relu5(x)
  
      x = self.layer4(x)
      x = self.conv6(x)
      x = self.bn6(x)
      x = self.relu6(x)
      f.append(x)
      return f
  
file_path: PaddleOCR/ppocr/modeling/backbones/table_master_resnet.py
imports: import paddle
  import paddle.nn
  import paddle.nn.functional
label_desc: Use image node_id 3 for calling the TableResNetExtra obj's underlying member method code with example usage: obj.forward(x) and returns: f